| Current File : //usr/share/doc/postgresql-9.2.24/html/view-pg-cursors.html |
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>pg_cursors</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REV="MADE"
HREF="mailto:pgsql-docs@postgresql.org"><LINK
REL="HOME"
TITLE="PostgreSQL 9.2.24 Documentation"
HREF="index.html"><LINK
REL="UP"
TITLE="System Catalogs"
HREF="catalogs.html"><LINK
REL="PREVIOUS"
TITLE="pg_available_extension_versions"
HREF="view-pg-available-extension-versions.html"><LINK
REL="NEXT"
TITLE="pg_group"
HREF="view-pg-group.html"><LINK
REL="STYLESHEET"
TYPE="text/css"
HREF="stylesheet.css"><META
HTTP-EQUIV="Content-Type"
CONTENT="text/html; charset=ISO-8859-1"><META
NAME="creation"
CONTENT="2017-11-06T22:43:11"></HEAD
><BODY
CLASS="SECT1"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="5"
ALIGN="center"
VALIGN="bottom"
><A
HREF="index.html"
>PostgreSQL 9.2.24 Documentation</A
></TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
TITLE="pg_available_extension_versions"
HREF="view-pg-available-extension-versions.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
HREF="catalogs.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="60%"
ALIGN="center"
VALIGN="bottom"
>Chapter 45. System Catalogs</TD
><TD
WIDTH="20%"
ALIGN="right"
VALIGN="top"
><A
TITLE="pg_group"
HREF="view-pg-group.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="VIEW-PG-CURSORS"
>45.55. <TT
CLASS="STRUCTNAME"
>pg_cursors</TT
></A
></H1
><P
> The <TT
CLASS="STRUCTNAME"
>pg_cursors</TT
> view lists the cursors that
are currently available. Cursors can be defined in several ways:
<P
></P
></P><UL
><LI
><P
> via the <A
HREF="sql-declare.html"
>DECLARE</A
>
statement in SQL
</P
></LI
><LI
><P
> via the Bind message in the frontend/backend protocol, as
described in <A
HREF="protocol-flow.html#PROTOCOL-FLOW-EXT-QUERY"
>Section 46.2.3</A
>
</P
></LI
><LI
><P
> via the Server Programming Interface (SPI), as described in
<A
HREF="spi-interface.html"
>Section 43.1</A
>
</P
></LI
></UL
><P>
The <TT
CLASS="STRUCTNAME"
>pg_cursors</TT
> view displays cursors
created by any of these means. Cursors only exist for the duration
of the transaction that defines them, unless they have been
declared <TT
CLASS="LITERAL"
>WITH HOLD</TT
>. Therefore non-holdable
cursors are only present in the view until the end of their
creating transaction.
</P><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> Cursors are used internally to implement some of the components
of <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>, such as procedural languages.
Therefore, the <TT
CLASS="STRUCTNAME"
>pg_cursors</TT
> view might include cursors
that have not been explicitly created by the user.
</P
></BLOCKQUOTE
></DIV
><P>
</P
><DIV
CLASS="TABLE"
><A
NAME="AEN94145"
></A
><P
><B
>Table 45-56. <TT
CLASS="STRUCTNAME"
>pg_cursors</TT
> Columns</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><COL><COL><COL><THEAD
><TR
><TH
>Name</TH
><TH
>Type</TH
><TH
>Description</TH
></TR
></THEAD
><TBODY
><TR
><TD
><TT
CLASS="STRUCTFIELD"
>name</TT
></TD
><TD
><TT
CLASS="TYPE"
>text</TT
></TD
><TD
>The name of the cursor</TD
></TR
><TR
><TD
><TT
CLASS="STRUCTFIELD"
>statement</TT
></TD
><TD
><TT
CLASS="TYPE"
>text</TT
></TD
><TD
>The verbatim query string submitted to declare this cursor</TD
></TR
><TR
><TD
><TT
CLASS="STRUCTFIELD"
>is_holdable</TT
></TD
><TD
><TT
CLASS="TYPE"
>boolean</TT
></TD
><TD
> <TT
CLASS="LITERAL"
>true</TT
> if the cursor is holdable (that is, it
can be accessed after the transaction that declared the cursor
has committed); <TT
CLASS="LITERAL"
>false</TT
> otherwise
</TD
></TR
><TR
><TD
><TT
CLASS="STRUCTFIELD"
>is_binary</TT
></TD
><TD
><TT
CLASS="TYPE"
>boolean</TT
></TD
><TD
> <TT
CLASS="LITERAL"
>true</TT
> if the cursor was declared
<TT
CLASS="LITERAL"
>BINARY</TT
>; <TT
CLASS="LITERAL"
>false</TT
>
otherwise
</TD
></TR
><TR
><TD
><TT
CLASS="STRUCTFIELD"
>is_scrollable</TT
></TD
><TD
><TT
CLASS="TYPE"
>boolean</TT
></TD
><TD
> <TT
CLASS="LITERAL"
>true</TT
> if the cursor is scrollable (that is, it
allows rows to be retrieved in a nonsequential manner);
<TT
CLASS="LITERAL"
>false</TT
> otherwise
</TD
></TR
><TR
><TD
><TT
CLASS="STRUCTFIELD"
>creation_time</TT
></TD
><TD
><TT
CLASS="TYPE"
>timestamptz</TT
></TD
><TD
>The time at which the cursor was declared</TD
></TR
></TBODY
></TABLE
></DIV
><P
> The <TT
CLASS="STRUCTNAME"
>pg_cursors</TT
> view is read only.
</P
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="view-pg-available-extension-versions.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="view-pg-group.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><TT
CLASS="STRUCTNAME"
>pg_available_extension_versions</TT
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="catalogs.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><TT
CLASS="STRUCTNAME"
>pg_group</TT
></TD
></TR
></TABLE
></DIV
></BODY
></HTML
>